1. Field of the Invention
The present invention relates to a scroll pump having a pump head assembly that includes a stationary plate scroll and an orbiting plate scroll, a pump motor coupled to the orbiting plate scroll so as to drive the orbiting plate scroll, and means for cooling one or more components of the pump. In particular, the present invention relates to a method of and means for regulating the temperature of components of a scroll pump.
2. Description of the Related Art
A scroll pump is a type of pump that includes a stationary plate scroll having a stationary plate and a spiral stationary scroll blade projecting axially therefrom, and an orbiting plate scroll having an orbiting plate and a spiral orbiting scroll blade projecting axially therefrom. The stationary and orbiting scroll blades are nested with a clearance and predetermined relative angular positioning, and a seal is provided between the tip (free end) of the scroll blade of one (or both of) the plate scrolls and the plate (or plates of) the other plate scroll such that a pocket (or pockets) is delimited by and between the stationary and orbiting scroll blades. The stationary plate scroll is fixed in the pump. The orbiting plate scroll and hence, the orbiting scroll blade, is coupled to an eccentric driving mechanism. The stationary and orbiting plate scrolls and the eccentric drive mechanism may make up what is referred to as a pump head or pump head assembly.
The eccentric drive mechanism is, in turn, connected to and driven by a motor of the pump such that the orbiting scroll plate orbits about a longitudinal axis of the pump passing through an axially central portion of the stationary scroll blade. The volume of the pocket(s) delimited by the scroll blades of the pump is varied as the orbiting scroll blade moves relative to the stationary scroll blade. The orbiting motion of the orbiting scroll blade also causes the pocket(s) to move within the pump head assembly such that the pocket(s) is selectively placed in open communication with an inlet and outlet of the scroll pump.
In an example of such a scroll pump, the motion of the orbiting scroll blade relative to the stationary scroll blade causes a pocket sealed off from the outlet of the pump and in open communication with the inlet of the pump to expand. Accordingly, fluid is drawn into the pocket through the inlet. Then the pocket is moved to a position at which it is sealed off from the inlet of the pump and is in open communication with the outlet of the pump, and at the same time the pocket is compressed. Thus, the fluid in the pocket is compressed and thereby discharged through the outlet of the pump.
In the case of a vacuum-type of scroll pump, the inlet of the pump is connected to a chamber that is to be evacuated. Conversely, in the case of a compressor-type of scroll pump, the outlet of the pump is connected to a chamber that is to be supplied with pressurized fluid by the pump. In either case, various components of the pump produce significant amounts of heat which may reduce the useful life of the components or worse, cause an operational failure of the pump.
Therefore, scroll pumps are provided with one or more cooling fans to cool the pump. However, the fan(s) may be a significant source of noise which is detrimental in the workplace.